Thanks for the tip, Mighty! I'll try that next time I do a lineart.

Nice drawing of Kaltag!

While it's not a big deal, I thought I would just throw the suggestion out there. While I understand drawing with a mouse can be difficult, there is a way to reduce the shakiness that is visible here.

The first step is to make a rough drawing using basic shapes and construction lines. I would suggest doing this in a lighter color, but not so light that you can no longer see it. Then switch back to black and ZOOM in. That is the key. While it may take you longer to create the lineart, being zoomed in does help. To clean up your lines to remove what is underneath, go to image> invert> image> attributes-black and white> image> invert.

With success, you should now have a clean lineart that is less shaky.